TThe Federal Women nested study was designed to help unravel the complex association of race/ ethnicity, hepatic insulin resistance and the pathway to diabetes. This project evaluated the components of hepatic glucose production (gluconeogenesis and glycogenolysis) and the contribution of hepatic to total body insulin resistance by race and ethnicity. Eligible women (30 African descent and 30 white) who participated in theprimary protocol (13-DK-0090) were invited to participate in the nested study to measure glucose and fat metabolism and energy expenditure. In 46 pre-menopausal federally-employed women, without diabetes: 24 black and 22 white; age 371 (meanSEM), range 25-49 y; BMI 321, range 24-45 kg/m2 we found lower gluconeogenesis (new glucose made by the liver) despite similar rates of whole-body insulin resistance and prediabetes. In addition, there was less insulin resistance in the liver in black women but no difference in insulin resistance in adipose (fat) tissue. These findings provided mechanistic insight to help understand why the fasting blood glucose test has lower sensitivity for detecting prediabetes/ diabetes in black women. Our findings have been published in major peer-review journals (The Journal JCI Insight and The Journal of Clinical Endocrinology and Metabolism). A third manuscript on the postprandial changes in lipoproteins is under review at Circulation Research.